1) Field of the Invention
The present invention relates to novel benzothiazepine compounds having a thioamide bond and a quaternary ammonium substituent and to pharmaceutical compositions which contain them. Moreover, the present invention relates to pharmaceutical compositions for the treatment of cholestasis-caused hepatopathy and the like.
2) Description of the Related Art
Hyperlipidemia means a state where neutral fat, cholesterol and the like in blood are at higher levels than the normal levels and has been known to deserve a treatment since it is a main risk factor in ischemic diseases. Moreover, hyperlipidemia is also known to cause arteriosclerosis and in particular, to decrease blood cholesterol level is effective for the prevention and treatment of arteriosclerosis. Arteriosclerosis is also known as a cause of myocardial infarction, cerebral thrombosis, peripheral arterial obstruction, and arteriosclerosis obliterans. Syndrome X was advocated by Reavens et al. (“Diabetes”, 37, 1595-1607, 1988) and means a multiple risk factor syndrome which develops arteriosclerosis by accumulation of risk factors such as hyperinsulinemia, hyperlipidemia, hypertension, and abnormality of glucose tolerance on an individual, although the factors are not so serious as to indicate the conditions of diseases when they exist independently of each other. A cholesterol-lowering agent is considered to be effective for the prevention or treatment of these diseases (Japan Clinical Hyperlipidemia—Volume 1—ISSN0047-1852).
At present, commercially available drugs for the treatment of hyperlipidemia include HMG-CoA reductase inhibitors, anion exchange resins and so forth. These drugs are used for the prevention and treatment of hyperlipidemia, in particular, hypercholesterolemia and arteriosclerosis. Furthermore, these drugs are also used in the prevention or treatment of myocardial infarction, cerebral thrombosis, peripheral arterial obstruction, and arteriosclerosis obliterans, which are diseases caused by hypercholesterolemia or arteriosclerosis.